macrumors 68020

How does this exactly work? I caught some of it in the keynote but not the entire thing. I'm just looking for details. Thanks in advance!

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The iPhone (4 and above) has special hardware on the cellular modem that can detect when leaving or entering a certain "region" on the map just with its usual semi-frequent pings to and from different cell towers. This means that GPS doesn't have to be turned on, thus not a lot of battery drain.

When you enter or leave a certain region that you define, you can have the phone remind you of something. This feature has also been available to developers to implement in their own apps since iOS 4.0.

macrumors regular

The iPhone (4 and above) has special hardware on the cellular modem that can detect when leaving or entering a certain "region" on the map just with its usual semi-frequent pings to and from different cell towers. This means that GPS doesn't have to be turned on, thus not a lot of battery drain.

When you enter or leave a certain region that you define, you can have the phone remind you of something. This feature has also been available to developers to implement in their own apps since iOS 4.0.

macrumors regular

If you have a 4s, ask Siri to remind you of something when you get to/leave a location (home, office, etc.). You will need to add these addresses in your contact profile of yourself.
If you have a 4, same thing, but all manually in the reminders app.

macrumors 6502a

You can ask Siri to "Remind me to do x when I leave here", and a reminder saying do x will pop up when you leave.

In practice this happens when I'm a few hundred yards away when driving, so not that practical, but better than forgetting something completely!

This uses the location services, which may use cell tower triangulation and/or GPS. Trying this at work today (where cell tower triangulation is poor due to poor coverage) my battery took quite a hit - I guess it was using GPS then?

macrumors 65816

The iPhone (4 and above) has special hardware on the cellular modem that can detect when leaving or entering a certain "region" on the map just with its usual semi-frequent pings to and from different cell towers. This means that GPS doesn't have to be turned on, thus not a lot of battery drain.

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Are you sure about that? My phone battery went down 15% in under and hour with a geolocation reminder set. I hope Apple fixes that, as it seems useful, but not if it's that taxing on the battery. Maybe it could check once every five minutes or so?

macrumors 68000

Are you sure about that? My phone battery went down 15% in under and hour with a geolocation reminder set. I hope Apple fixes that, as it seems useful, but not if it's that taxing on the battery. Maybe it could check once every five minutes or so?

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I have noticed when I create a georeminder, my gps arrow stays constantly on. This would put a serious dent in battery life no?

macrumors 6502a

I have noticed when I create a georeminder, my gps arrow stays constantly on. This would put a serious dent in battery life no?

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I think the arrow is a 'location services' arrow, not strictly a GPS arrow. As others have stated, the iPhone uses assisted GPS to determine location, so it uses cell tower triangulation and wi-fi hotspot positioning to help determine position. If these other positioning services (which use less power than GPS) give a good 'quality' position, the iPhone probably relies more on these than GPS, but where these are poor, the GPS will be used. I also suspect the GPS might only be activated every minute or so for reminders, but it still does hit battery life.

macrumors 68000

There is a problem I have been experiencing with this when I turn wifi off. I get the notices as if I have arrived or left the location, even though I am over a mile away. It seems to need some more work.

macrumors 6502a

No idea exactly how the Geo-fence works, but I did notice that if the address isn't exact, the reminder doesn't go off.

For example, went to my parents house which is in a rural area. There address is 149 Main Street (for example).

My reminder never went off.

When I was there, I noticed the reminders app thought the current location was 66 - 269 Main Street.

So if it's not exact, then it doesn't seem to work.

-Kevin

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I have noticed the same problem in the UK. Our post codes (ZIP codes) are georeferenced, but one post code can cover several houses, and the georeference position for our post code is some distance from our house.

It would be better if Apple:

1) let one add the GPS Lat long position of addresses (e.g. Home), and/or
2) let you create an 'event' that signalled leaving a location e.g. the loss of signal from a specific wi-fi station. The signal from our wi-fi router at home is lost half way down our drive, so it would be a very precise reminder location for leaving/arriving at home, and it wouldn't need the power-hungry GPS.

macrumors 6502

I noticed a sudden increase in battery usage when using a geofence reminder too- something like a 15% drop over an hour which seems pretty consistent with full use of GPS. Nice feature, but too much battery drain to be useful for me.

Siri, remind me to plug in my phone when I go home or to work because your geofence feature kills my battery!

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